The gemara (Sukka 47a) determines that outside Israel, one must eat in the sukka on Shemini Atzeret, but without reciting the berakha of "leisheiv ba-sukka." Various explanations have been given for this. The Rambam sees this as an example of a general rule, namely that no berakha is made when a mitzva is performed based on a safek (doubt) - in this case, the safek that perhaps the day celebrated as Shemini Atzeret outside Israel is in fact the seventh day of Sukkot. Tosafot (Sukka 47a) imply that making a berakha would be tantamount to treating the chag like an ordinary workday (since during chol ha-mo'ed we also make a berakha and work is permitted), though sitting in the sukka alone is not as problematic, since "a person often finds it pleasant to eat in the sukka even on days of Yom Tov [when it is not necessary to do so]."

We will focus on the explanation given by the Rif:

"Since it is Shemini Atzeret, making a berakha would lead to a contradiction: if it is a day of [sitting in the] sukka, then it is not Shemini Atzeret, and if it is Shemini Atzeret, then it is not a day of [sitting in the] sukka! Since we are in doubt, we act stringently on both counts. We eat in the sukka but make no berakha and treat the day as chag (i.e., Shemini Atzeret)."

The Rif is somewhat difficult to understand. He claims that making a berakha would imply that one MUST sit in the sukka on that day, and this is inconsistent with the character of Shemini Atzeret. Yet it would seem that SITTING in the sukka without a berakha implies the same thing! It is difficult to explain that the Rif is relying on the explanation of Tosafot quoted in the last paragraph, since he does not mention this at all.

The explanation of the Rif is adopted by the Sefer Ha-chinukh (chapter 323), who explains it in greater detail. According to the Chinukh, the reason we make no berakha on sitting in the sukka on Shemini Atzeret relates to the essence of Shemini Atzeret itself. While the gemara (Sukka 47a) lists various ways in which Shemini Atzeret is considered a holiday in and of itself, it nonetheless refers to the day as "the closing yom tov of Sukkot" (Sukka 48a). The question which naturally arises is, should Shemini Atzeret be viewed fundamentally as an independent chag, or rather as the end of Sukkot? This question could lie at the heart of the debate among poskim regarding the proper reference to Shemini Atzeret in Ya'aleh Ve-yavo: should one say "chag ha-atzeret," festival of closing, or "atzeret ha-chag," closing of the festival (the latter suggesting that the day is the conclusion of the "chag," namely Sukkot)? The Chinukh opts for the first formulation, thus emphasizing the independent character of the day: "There is no reference made to Sukkot in this formulation at all." Why, then, do we sit in the sukka on Shemini Atzeret? The Chinukh continues:

"Chazal commanded us to sit in the sukka to fulfill the obligation [of Jews outside Israel] to add one day to every holiday; hence, we add a day to Sukkot and make it eight days, but we don't make a berakha on the sukka on that day because it is really a different holiday altogether. Since nowadays we know the calculation of the calendar and hence the true date, it is more appropriate to make berakhot relating to the true character of the day rather than to the aspect of the day instituted by Chazal. Although one may ask: why do we not mention both Sukkot and Shemini Atzeret in our blessings, as we do with regard to Shabbat and Yom Tov when they coincide? [The answer is] we find that it is possible for Shabbat and Yom Tov to occur on the same day, but TWO DIFFERENT HOLIDAYS CANNOT OCCUR AT THE SAME TIME, and hence we should not recite such a berakha. But it is perfectly appropriate to sit in the sukka on Shemini Atzeret, SINCE THIS DOES NOT DETRACT FROM THE HOLIDAY OF SHEMINI ATZERET AT ALL."

The Chinukh's explanation of the Rif may be summarized as follows: with regard to the berakha, the seventh and eighth days are mutually exclusive, and for that same reason we can't mention both Sukkot and Shemini Atzeret in our blessings, since "two different holidays cannot occur at the same time." However, sitting in the sukka itself on the eighth day is fine because "this does not detract from the holiday of Shemini Atzeret at all."

While the Rif's language is terse, the Chinukh provides an explanation. According to the Chinukh, the entire problem would not have arisen had Shemini Atzeret not been an independent holiday. Had the eighth day been part of Sukkot, we would have been able to sit in the sukka and even make a berakha, and there would have been no conflict between Sukkot and Shemini Atzeret. The problem lies not in the fact that there is no OBLIGATION to sit in the sukka on the Shemini Atzeret, but in the fact that Shemini Atzeret IN ITS ESSENCE is a holiday separate and different from Sukkot. Thus, for instance, we have no problem making a berakha of "al akhilat matza" on the second night of Pesach outside Israel, despite the fact that there is no obligation from the Torah to eat matza then; this is because the second night of Pesach is part of the holiday of Pesach, while Shemini Atzeret itself is detached from and independent of Sukkot. The Chinukh believes that we need be concerned about the problem of mutual exclusion only with regard to two entirely different and conflicting characteristics which we attempt to impose on the same one day.

As explained, according to the Rif and the Chinukh, sitting in the sukka alone does not represent such a problem of mutual exclusion, while making a berakha over the sukka would be problematic and is comparable to mentioning both Sukkot and Shemini Atzeret in the same berakha. The novelty of this approach is that it considers the berakha of "leisheiv ba-sukka" not simply as a berakha made on a mitzva but as a berakha which serves to impart to the day itself the character of the holiday of Sukkot. Thus, this berakha stands in contradiction to the tefillot recited throughout the eighth day, in which we refer to the day as "this holiday of Atzeret" and impart to the day the character of Shemini Atzeret. In addition, since we have to mention "chag ha-atzeret" we have to leave out any mention of Sukkot. This approach, while fully explained by the Chinukh, can also be inferred from the words of the Rif quoted earlier: "If it is aDAY OF[eating in the] SUKKA, then it is not Shemini Atzeret, and if it is Shemini Atzeret, then it is not a DAY OF [eating in the] SUKKA." The contradiction lies not in the act of making a berakha but in the character ascribed to the day by the berakha.

A BERAKHA ON A MITZVA ESTABLISHES THE CHARACTER OF THE DAY

This explanation assumes, as noted, the novel assumption that the berakha on the mitzva of sitting in the sukka establishes the character of the day as a "day of sukka" and therefore the berakha, not the sitting itself, undermines the independent status of Shemini Atzeret. The Rambam, too, seems to accept this assumption. We have already noted that in his opinion, the reason we make no berakha on the mitzva of sukka on Shemini Atzeret is that we do not make berakhot on mitzvot performed due to a safek. But this is somewhat difficult, because we recite such berakhot on every added day of Yom Tov outside Israel (the berakha made over matza on the second night of Pesach, alluded to earlier, is but one example), and these days are only safek Yom Tov. The Rambam himself referred to this in a response to the elders of Lunel (quoted in the Kesef Mishneh, Hilkhot Mila 3:6): "[The second day of Yom Tov] was itself created out of a safek, and Chazal established on that day all the berakhot associated with it, just like the first day of Yom Tov." That is to say, were it true that we eat matza on the second night of Pesach solely due to the safregarding the fulfillmethe previous night of the mitzva to eat matza, we would not make a berakha. But since Chazal IMBUED THE ENTIRE SECOND DAY with the sanctity of the first day of Yom Tov due to a safek, we may recite all the berakhot associated with the mitzvot of the day. The reason is as we explained in the Rif and the Chinukh: reciting berakhot on the mitzvot of the day helps also to fulfill and establish the sanctity of the day itself.

Thus, it turns out that the Rambam and the Rif do not disagree in the reasons they give for not making the berakha over sukka on Shemini Atzeret. The Rambam establishes that we cannot recite the berakha due merely to the safek of whether we are fulfilling the mitzva of sukka, since berakhot are not made over mitzvot in such situations. However, we would still believe that the berakha should be recited as an integral part of the rabbinically ordained sanctity of the day, just as we recite the berakha over matza on the second night of Pesach. To reject this reasoning, we need the explanation of the Rif regarding the mutual exclusion of the character of Sukkot and the character of Shemini Atzeret.

IS SHEMINI ATZERET A "SECOND DAY OF YOM TOV" AT ALL?

We have seen that (in the opinion of the Rif) no berakha is made on the mitzva of sukka on Shemini Atzeret because this berakha undermines the sanctity of Shemini Atzeret inherent in the day. But the question arises: doesn't the undermining of the sanctity of the day still exist simply by virtue of the institution of the second day of Yom Tov? Just as the second day of Sukkot is imbued by Chazal with the sanctity of the first day, so too the eighth day - Shemini Atzeret - is imbued with the sanctity of the seventh day of Sukkot and hence represents a rabbinic "day of sukka" undermining the sanctity of Shemini Atzeret! When we refrain from reciting the berakha over the mitzva of sukka on the eighth day, it seems that we are simply closing our eyes to the fundamental contradiction inherent in the day. Is it conceivable that Chazal recognized this contradiction and commanded us to HIDE it to the greatest possible extent by not alluding to it in our prayers or in our berakhot?!

But we can deal with this difficulty in a much more direct manner by suggesting that the "sefeika de-yoma" (doubt relating to the identity of the day) with regard to Shemini Atzeret is different from that of the usual second day of Yom Tov. With regard to every other Yom Tov, Chazal instituted that nowadays (when we know the true date with certainty) the second day is a "rabbinic Yom Tov," imbued with the sanctity of the first day, as explained earlier. But Shemini Atzeret was not instituted as a "rabbinic seventh day of Sukkot;" rather, we are simply commanded to perform all the mitzvot of Sukkot on Shemini Atzeret out of doubt, as if we were really concerned that the day might truly be the seventh day of Sukkot. With regard to the essential nature and sanctity of the day, Shemini Atzeret is not a "day of sukka" at all.

Evidence for this suggestion is provided by the discussion of Rishonim regarding why we do not perform the mitzva of lulav on Shemini Atzeret but nevertheless still sit in the sukka. One suggested answer is that lulav is only a rabbinic mitzva on the seventh day of Sukkot. Rav Soloveitchik pointed out a major difficulty with this answer: maror is only a rabbinic mitzva nowadays, yet we perform this mitzva (and with a berakha) on the second night of Pesach! It would seem that this answer relies on a fundamental distinction between Shemini Atzeret and other days of safek Yom Tov such as the second day of Pesach. Other days of safek Yom Tov have (on a rabbinic level) the sanctity and character of the previous day, and hence all obligations associated with the previous day are in force. Shemini Atzeret, in contrast, has no character of Sukkot at all; rather, we are commanded by Chazal to perform the mitzvot of Sukkot on that day out of concern that the calendar is one day off. This stringency was instituted only with regard to biblical mitzvot, and hence we sit in the sukka but do not perform the mitzva of lulav which is a rabbinic mitzva on this day.

THE SITTING IN THE SUKKA OF SHEMINI ATZERET DIFFERS FROM THAT OF THE REST OF SUKKOT

Finally, one additional point must be examined. The Rif applies his explanation to the berakha of "leisheiv ba-sukka" but not to the sitting in the sukka itself, since, as the Chinukh explained, "this does not detract from the holiday of Shemini Atzeret at all." But we could conceivably claim that the sitting too should be problematic if we assume that it too, like the berakha, defines the character of the day. This would obviously prevent us from making any distinction between the berakha on sitting in the sukka and the sitting itself; both serve to define the character of the day and hence both should be prohibited on Shemini Atzeret according to the Rif. But we could still suggest that there are two aspects to the mitzva of sitting in the sukka; it is on the one hand a mere act ("ma'aseh mitzva") we are commanded to perform on certain days of the year, and on the other hand it defines and fulfills the sanctity and character of those days. Perhaps different activities representing different levels of dwelling in the sukka can be associated with each of these aspects: the bare essentials of eating and sleeping in the sukka are part of the "ma'aseh mitzva" of sitting in the sukka, while additional acts such as strolling in the sukka and bringing fine utensils into the sukka, which transform the sukka into a person's natural environment for the duration of the holiday, serve to define the character of the day as a "day of sukka." If we apply the idea of the Rif to this framework, we may suggest that the requirement of sukka on Shemini Atzeret is to perform the "ma'aseh mitzva" of SITTING IN THE SUKKA, but NOT to transform the sukka into a PERSON'S NATURAL DWELLING - since this would define the day as a "day of sukka."

This seems to be the opinion of the Bach (OC, 666). The mishna (Sukka 48a) states that on the afternoon of the seventh day of Sukkot, a person must bring his utensils from the sukka back into the house, out of respect for the upcoming Yom Tov. Presumably, this requirement exists only in Israel, where people eat in the house on Shemini Atzeret and hence require their utensils to be in the house. The Bach, however, suggests that this halakha applies even outside Israel; though we eat in the sukka, we must still remove beforehand from the sukka all the fine utensils and leave only the utensils required for eating. The opinion of the Bach must be that we can fulfill on Shemini Atzeret only the "ma'aseh mitzva" of sitting in the sukka and must not perform the higher level of transforming the sukka into a natural dwelling, since this would define the day as a "day of sukka" and thereby undermine the independent character of Shemini Atzeret.